Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Energy Changes in Systems
Question Paper
Level
Subject
Exam Board
Topic
Sub-Topic
Difficulty Level
Booklet
Time Allowed:
GCSE (9-1)
Combined Science: Trilogy - Physics
AQA
6.1 Energy
Energy Changes in Systems
Gold Level
Question Paper
39 minutes
Score:
/37
Percentage:
/100
Grade Boundaries:
Page 1
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Q1.Figure 1 shows a kettle a student used to determine the specific heat capacity of water.
Figure 1
© vladimirkim3722/iStock/Thinkstock
The student placed different masses of water into the kettle and timed how long it
took for the water to reach boiling point.
The student carried out the experiment three times.
The student’s results are shown in the table below.
Time for water to boil in seconds
(a)
Mean
Mass ×
change in
temperature
in kg°C
Energy
supplied in
kJ
63
59
20
131
110
116
110
40
243
140
148
141
143
60
314
1.00
184
190
183
182
80
401
1.25
216
215
211
214
100
471
1.50
272
263
266
267
120
587
1.75
298
300
302
Mass of
water in kg
1
2
3
0.25
55
60
0.50
105
0.75
140
Suggest how the student was able to ensure that the change in temperature was the
same for each mass of water.
........................................................................................................................
........................................................................................................................
........................................................................................................................
Page 2
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
........................................................................................................................
(2)
(b)
Calculate the uncertainty in the student’s measurements of time to boil when the
mass of water was 1.75 kg.
........................................................................................................................
........................................................................................................................
Uncertainty = ....................................... s
(2)
(c)
The power rating of the kettle is 2.20 kW.
Calculate the average electrical energy used by the kettle, in kJ, for 1.75 kg of water
to reach boiling point.
........................................................................................................................
........................................................................................................................
........................................................................................................................
Average energy = ........................................... kJ
(2)
(d)
Use information from the table above to calculate the change in temperature of the
water during the investigation.
........................................................................................................................
........................................................................................................................
Change in temperature = ................................. °C
(2)
(e)
The student plotted a graph of energy supplied in kJ against mass × change in
temperature in kg °C.
Figure 2 shows the graph the student plotted.
Figure 2
Page 3
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Use data from the table above to plot the four missing points.
Draw a line of best fit on the graph.
(3)
(f)
Use the graph to determine the mean value of the specific heat capacity of water, for
the student’s investigation.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Specific heat capacity of water = ........................... J / kg °C
(4)
(g)
The student’s value for the specific heat capacity of water was greater than the
accepted value.
Suggest why.
........................................................................................................................
Page 4
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
........................................................................................................................
(1)
(h)
The kettle used in the experiment had a label stating that the power rating of the
kettle was 2.2 kW.
The student did not measure the power of the kettle.
Suggest why measuring the power of the kettle may improve the student’s
investigation.
........................................................................................................................
........................................................................................................................
(1)
(Total 17 marks)
Q2.The figure below shows a rollercoaster.
The rollercoaster car is raised a vertical distance of 35 m to point A by a motor in 45
seconds.
The mass of the rollercoaster is 600 kg.
The motor has a power rating of 8 000 W.
(a)
Calculate the percentage efficiency of the motor.
Gravitational field strength = 9.8 N / kg.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Page 5
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
........................................................................................................................
........................................................................................................................
........................................................................................................................
Efficiency = ................................... %
(5)
(b)
The rollercoaster rolls from point A to point B, a drop of 35 m.
Calculate the speed of the roller coaster at point B.
Assume that the decrease in potential energy store is equal to the increase in kinetic
energy store.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Speed at point B = ................................... m / s
(6)
(Total 11 marks)
Q3.An electric immersion heater is used to heat the water in a domestic hot water tank.
When the immersion heater is switched on the water at the bottom of the tank gets hot.
Page 6
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
(a)
Complete the following sentence.
The main way the energy is transferred through the copper wall of the water tank is
by
the process of ................................................................................ .
(1)
(b)
The immersion heater has a thermostat to control the water temperature.
When the temperature of the water inside the tank reaches 58°C the thermostat
switches the heater off. The thermostat switches the heater back on when the
temperature of the water falls to 50°C.
Graph A shows how the temperature of the water inside a hot water tank changes
with time. The tank is not insulated.
Time in hours
(i)
The temperature of the water falls at the fastest rate just after the heater
switches off.
Page 7
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Explain why.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(ii)
To heat the water in the tank from 50°C to 58°C the immersion heater
transfers 4032 kJ of energy to the water.
Calculate the mass of water in the tank.
Specific heat capacity of water = 4200 J/kg°C
...............................................................................................................
...............................................................................................................
...............................................................................................................
Mass = .............................................................. kg
(3)
(iii)
An insulating jacket is fitted to the hot water tank.
Graph B shows how the temperature of the water inside the insulated hot
water tank changes with time.
Time in hours
Page 8
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
An insulating jacket only costs £12.
By comparing Graph A with Graph B, explain why fitting an insulating jacket
to a hot water tank saves money.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(3)
(Total 9 marks)
Page 9